I've had a couple people confuse the 'Most Online Today' stat at the bottom of the forum as meaning the total visitors for the day. It actually shows the number of simultaneous visitors in a 30 minute window.

So for example, on the Wimbledon final this year:

We broke the 'Most Online Today' record at 1770 visitors which was within a 30 minute window.

But more importantly, the number of total visitors for that day was actually a record breaking 31,765 visitors.